Mobile phones and other mobile terminals are one of the equipment that people in today's society cannot be separated therefrom. In order to improve the convenience of mobile phones, mobile phones are getting smaller and thinner but still cannot meet the needs of the people. For example, the mobile phone generally uses the LED flash lamp as a flashlight, but the LED flash lamp is originally designed for compensating the light while photographing and the light is generally scattered light and cannot be converged, thus, the Irradiation distance is short. Also, when people in a meeting and usually need to use a laser pointer or a page-turning laser pointer. If forgot to bring one, the user may feel inconvenient and the effect of PPT demonstration may be affected. In addition, sometimes people may want to quickly know the distance between two objects but without a tape with them, thus, it will be a great convenience to the people if the mobile phone has a distance-measuring function.